Printing-frame.



2; a. PECHUQRAPEY. Primin Frames.

PATENTED NOV. 6, 1906.

E. w. SWEIGARD. PRINTING FRAME.

APPLICATION FILED APB. 19,1906.

uNrrEn., sTArEs PATENT OFFICE- EMANUEL W. SWEIGARD, OF CHICAGO, ILLINOIS.

PRINTING-FRAME.

Specification of Letters Patent.

.Patented. Nov. 6, 1906.

' Application filed April 19, 1906. Serial No. 812,638.

GARD, a citizen of the United States of Amerin said patent.

ica, residing at Chicago, in the county of Cook and State of Illinois, have inventedcertain new and useful Improvements in Printing-Frames, of which the following is a specification.

My invention relates to improyements in printing-frames, and is. fully described and explained in this specification and shown the accompanying drawings, inwhich {a r Figure 1 is a side elevation ofiny improved device. Fig. 2 is a vertical sectionin the line 2 2 of Fig. 3. Fig. 3 is a front elevation of one of the bar-clamping devices, and Fig. 4 is an elevation of that portionof-the clamp; ing device which is secured to the printingframe proper.

The frame herein illustrated is intended a an improvement in certain particulars upon that shown and described in my patent granted May 10, 1898, No. 603,713, and it will be observed that for the most part my device shows the general construction shown Thus A is a hollow rectangular frame adapted to receive a plate of glass B, upon which a negative C is laid with its film side u and upon this negative 0 is laid the print which may be either a sheet of sensitized paper, or, more often, a sheet of zinc, such as is used in photo-engraving and like processes. Upon this print, as I shall call it for convenience, is placed a pressureboard E, upon the back of which are placed a number of elastic struts or cushions F, of rubber or other desired material, which may be arranged as shown in my prior patent or in other ways, as desired. Along the rear of the frame are secured a plurality of hinges g, which su port a plurality of swinging bars G, which when pressed down at their forward ends will clamp the pressure-board against the plate, thus producing the proper contact between the rint and the negative. Along the front of t e frame A are secured a plurality of brackets H, provided with furcations h, adapted to receive between them the upwardly-projecting ends of bifurcated members I, mounted upon the forward ends of the bars G. The furcations of the brackets operate to receive said members, and thereby to center and position the forward ends of the bars G, which, owing to the imperfections in the hinge construction at the rear thereof, have necessarily some lost motion in a horizontal lane. The members I support between t eir furcations levers .J each of which is provided with an elongated handle and a recurved hook fimrtion 7" The brac ets II support loops ca able of swinging backward andsforward, til being limited by contact with-the frame A and the forward movement being limited by shoulders h on the bracket II. It will be seenthat these loo s when in their forward positidn (shown in, ig. 2) strike the handle 7' of the lever J andthat by rotating said levers th'e'loop's, willbe caused to pass-between the handle, and the hooked portion of said lever, so that when the levers are turned back over the frame, as shown in Fig. -1, the loops will have moved to the-position shown there-, in,so as'toproduce a toggle-clamping action on the ressure-board,

The-- "ve'r J, is provided with a hump J, ust behind that portion of the lever which is first struck by the 100 as the pressure-bar is swung downward. f this hump were omitted and the lever were straight from the point where the loop is showlrty in contact therewith, Fig, 2, upto the base df the hooked portion, assuming tht the lever and loop would slide on each 0 er with a fair degree of ease and that there was no undue binding between the loop and bracket, the contact of e backward movement the lever with the loop would merely cause the loop to slide up alon the lever, a wedging action taking place to e eat this result. The loop would sllde'up to the very base of the hook portion and would thenbein no position to exert any rotating tendency upon evers upon the forcible throwing down of the bars, the loops tend merely to slide up the levers until they reach substantially the dead-center and then exert no rotating force thereon. If, however, the friction between the loops and brackets is higher than normal, this inward movement of the loops will be prevented, and the throwing down of the bars will cause the lever to swing around so as to clamp the bars automatically, and this is the operation set out in the patent. This action only takes place, however, in the device of the patent when the friction between the brackets and loops is considerable, and it tends to disappear, therefore, as the device becomes worn.

My present inventionx-is-designed primarily to produce a structure which will lock itself automatically under all conditions, and this result is produced by placing the hump 5 J upon the lever. By this means the surface of the lever against which the loop strikes is almost at right angles to the loop,

and there is consequently little or no tendency for the 100 to slide upward along the mo lever instead of rotatingit. As a result, withmy present device, regardless ofthe amount of friction and the-force withwhich the cross-bar is thrown down, the loop re mains in its: forward position and causes rotation of thelever: about itspivot until it almost reaches the dead-center, and backward movement of the loop is never caused by its sliding up along-thebottom face of: the lever with awedge-likeaction, but rather by engagement with the-surface of the recurved hook portion 7" thereof. In other words, my present device isso arranged that the anglebetween the surface of the lever with which the-loop first contacts-and those portions-of the surface withwhich-it remainsin contact as the lever rotates is such that there is no-wedging forceexerted which canv move the loop backward. In fact, this angle is-substantia y-a right angle, so that there is never any wedging tendency, or, if any such tendency should exlst, it is one which. tends.

means forlimiting the forward swingof themeans for-limiting the forward swing of the loop, and a hooked lever pivoted to the cross-bar and adapted to engage the loop, the portion of the lever which contacts with the loop when the bars are swung down being so arranged as to resist the inward movement of the loop along the lever.

2. The combination with a frame, of a hinged cross-bar, a loop pivoted to the frame adjacent to the forward end of the cross-bar, :5 means for limiting the forward swing of the loop, and a hooked-lever pivoted to the crossbar and adapted to engage the loop, the P01?- tion of the lever which contacts with the loop;being so arranged as to present. a surface substantially at right. angles to the loopon the initial contact of the lever and loop;.

3. The combination with a frame, of a hinged cross-bar, a loop pivoted to theframe adjacent to the forwardend of the cross-bar,- means for limiting the forward swing of the loop, and a hooked lever pivoted to thecrossbar and adapted to-engage the loop,.the por-- tionof the lever which contacts withthe loop being so arranged as to: cause no inward. wedging of the loop..

4-. The combination with; a: frame, of a, hinged cross-bar, a loop pivoted to the frameadjacent to the forward endfof' the cross-bar,

'75 loop,v and a lever provided with a recurved hook. adapted to engage the loop pivotedupon the cross-bar, said lever being provided with a hump within the-hook, and inposition to strike the loop when in its forward posivtion and to prevent the said wedging of the hook'with the rotation'of the lever.

In witness-whereof I have signed the aboveapplication for-Letters Patent, at Chicago, in the county of Cook and State of Illinois, this 17th day of April, A. D. 1906.

EMANUEL W. SWEIGARD.

Vitnesses RUssELL WILES, E. BRAUN. 

